Nav: Home

Exposure to benzene during pregnancy: a pilot study raises concerns in British Columbia

November 13, 2017

Peace River Valley, in northeastern British Columbia, has become known in recent years as a place of hydraulic fracturing for natural gas - "fracking," as it's commonly called. What are the health impacts related to living near fracking sites where contaminants, including volatile organic compounds, are released? To try to answer that question, Élyse Caron-Beaudoin, a postdoctoral researcher at the Université de Montréal Public Health Research Institute, studied a group of pregnant women who live in the area. Her results were published this week in Environment International.

High concentrations of muconic acid - a degradation product of benzene (a volatile, toxic and carcinogenic compound) - were detected in the urine of 29 pregnant women who participated in the pilot study. Their median concentration of muconic acid was approximately 3.5 times higher in these women than in the general Canadian population.

In five of the 29 participants, the concentration of muconic acid surpassed the biological exposure index (BEI), a measure developed by the American Conference of Governmental Industrial Hygienists (ACGIH) to protect the health of people in the workplace. Caron-Beraudoin informed the five women of the results and communicated with their attending physicians. Guidelines of acceptable amounts of muconic acid in urine exist only for the workplace; there are none for the general population.

Not beyond a reasonable doubt

"Although the levels of muconic acid found in the participants' urine cannot prove beyond a reasonable doubt that they were exposed to high levels of benzene, these results do clearly demonstrate the importance of exploring human exposure to environmental contaminants in natural-gas (fracking) regions," said Marc-André Verner, the lead researcher on the study. Verner is a professor at Université de Montréal's School of Public Health and specializes in toxicological risk assessment.

"Muconic acid is also a degradation product of sorbic acid, which is often used as a preservative in the food industry," said Caron-Beaudoin. "However, we believe that diet alone is unlikely to explain the concentrations we found in our participants. A more extensive study needs to be conducted with additional measures - to test the air and drinking water, for example - to confirm or refute the results of our pilot study."

Health hazards of benzene include birth defects

The health impacts of benzene are well-documented. "High exposure to benzene during pregnancy is associated with low birth weight, an increased risk of childhood leukemia and a greater incidence of birth defects such as spina bifida," said Caron-Beaudoin. "We were therefore very concerned when we discovered high levels of muconic acid in the urine of pregnant women."

It should be noted that there are multiple routes of exposure to benzene, including inhaling cigarette smoke, filling your car's gas tank, driving, and drinking benzene-contaminated water.

"Many reports have been written on the contamination of air and water by volatile organic compounds near natural-gas well sites," said Verner, who is also a researcher at the Public Health Research Institute. "Northeastern British Columbia is a region that supports the use of hydraulic fracturing for natural gas. Despite the fact that many chemicals used or emitted by this industry are toxic to humans, no biological monitoring programs have been implemented in the region."

Indigenous people at the root of the study

Why did Quebec researchers lead a study exploring a public-health issue that mainly concerns people in Western Canada? Good question, Caron-Beaudoin replied. "At a conference, Professor Verner and I learned that certain indigenous communities, including the West Moberly First Nations, were concerned about the contaminants released by the many natural-gas sites on their territory, and about how this was affecting people's health. They were looking for researchers to conduct a formal impact study. We expressed our interest, but were very surprised that this kind of study had never been carried out before."

Among the pilot study's 29 participants, 14 were indigenous. Results revealed that the median concentration of muconic acid in the urine of these 14 women was 2.3 times higher than in non-indigenous participants, and six times higher than in women from the general Canadian population. However, it is important to note that the different levels found in indigenous and non-indigenous participants was not statistically significant, possibly due to the small number of women involved. A study with a larger sample size would be necessary to verify if this difference is significant.

'Environmental racism' - a new concept

Nonetheless, these results raise the issue of "environmental racism," a concept that is being increasingly explored by public-health researchers. Environmental racism refers to intentional or unintentional discrimination in the development and implementation of environmental policy, which disproportionately favours the installation of facilities that are potentially harmful to human health in areas populated by cultural minorities and in low-income communities.

For example, a study done in 2016 in Texas (Johnston et al., 2016*) revealed that wells used to dispose of wastewater coming from hydraulic fracturing sites were disproportionately permitted near communities with higher proportions of people of colour. "Environmental injustice is a major concern, particularly in indigenous communities where health inequalities are already an issue," said Verner.

A large-scale study now needed

What's next? Caron-Beaudoin and Verner have applied for funding from the Canadian Institutes of Health Research to conduct a major study of 100 pregnant women, using the same research methodology as in their pilot study. The study will involve doing an analysis not only of benzene biomarkers and other volatile organic compounds, but also of certain heavy metals in urine and hair samples. An environmental analysis of the participants' exposure to contaminants in the air and water will also be conducted. The data will then be modeled by Verner to estimate the fetal concentrations of these compounds, and thus more adequately measure the effects this type of exposure has on fetal development.

A second study led by Caron-Beaudoin will examine the medical data of approximately 6,000 babies born in the region over the past 10 years. "The goal is to assess the overall health of the babies (birth weight, pre-term births, head circumference and the prevalence of certain congenital birth defects) in relation to their proximity to natural-gas well sites and the number of active wells in their environment," the researcher said.
-end-
About the study

Élyse Caron-Beaudoin, Naomi Valter, Jonathan Chevrier, Pierre Ayotte, Katherine Frohlich and Marc-André Verner, "Gestational exposure to volatile organic compounds (VOCs) in Northeastern British Columbia, Canada: A pilot study", Environment International, published online on November 6, 2017. doi: 10.1016/j.envint.2017.10.022 This study was funded by the Université de Montréal Public Health Research Institute New Initiative Research Grant and by the West Moberly First Nations.

University of Montreal

Related Public Health Articles:

Public health guidelines aim to lower health risks of cannabis use
Canada's Lower-Risk Cannabis Use Guidelines, released today with the endorsement of key medical and public health organizations, provide 10 science-based recommendations to enable cannabis users to reduce their health risks.
Study clusters health behavior groups to broaden public health interventions
A new study led by a University of Kansas researcher has used national health statistics and identified how to cluster seven health behavior groups based on smoking status, alcohol use, physical activity, physician visits and flu vaccination are associated with mortality.
Public health experts celebrate 30 years of CDC's prevention research solutions for communities with health disparities
It has been 30 years since CDC created the Prevention Research Centers (PRC) Program, currently a network of 26 academic institutions across the US dedicated to moving new discoveries into the communities that need them.
Public health experts support federally mandated smoke-free public housing
In response to a new federal rule mandating smoke-free policies in federally funded public housing authorities, three public health experts applaud the efforts of the US Department of Housing and Urban Development to protect nonsmoking residents from the harmful effects of tobacco exposure.
The Lancet Public Health: UK soft drinks industry levy estimated to have significant health benefits, especially among children
The UK soft drinks industry levy, due to be introduced in April 2018, is estimated to have significant health benefits, especially among children, according to the first study to estimate its health impact, published in The Lancet Public Health.
Social sciences & health innovations: Making health public
The international conference 'Social Sciences & Health Innovations: Making Health Public' is the third event organized as a collaborative endeavor between Maastricht University, the Netherlands, and Tomsk State University, the Russian Federation, with participation from Siberian State Medical University (the Russian Federation).
Columbia Mailman School Awards Public Health Prize to NYC Health Commissioner Dr. Mary T.
Dr. Mary T. Bassett, Commissioner of the New York City Department of Health and Mental Hygiene, was awarded the Frank A.
Poor health literacy a public health issue
America's poor record on health literacy is a public health issue, but one that can be fixed -- not by logging onto the internet but by increased interaction with your fellow human beings, a Michigan State University researcher argues.
Despite health law's bow to prevention, US public health funding is dropping: AJPH study
Although the language of the Affordable Care Act emphasizes disease prevention -- for example, mandating insurance coverage of clinical preventive services such as mammograms -- funding for public health programs to prevent disease have actually been declining in recent years.
'Chemsex' needs to become a public health priority
Chemsex -- sex under the influence of illegal drugs -- needs to become a public health priority, argue experts in The BMJ this week.

Related Public Health Reading:

Introduction to Public Health
by Mary-Jane Schneider (Author)

The Health Gap: The Challenge of an Unequal World
by Michael Marmot (Author)

Public Health: A Very Short Introduction (Very Short Introductions)
by Virginia Berridge (Author)

Public Health: What It Is and How It Works
by Bernard J. Turnock (Author)

Public Health Nursing: Population-Centered Health Care in the Community, 9e
by Marcia Stanhope RN DSN FAAN (Author), Jeanette Lancaster RN PhD FAAN (Author)

A History of Public Health
by George Rosen (Author), Elizabeth Fee (Introduction), Pascal James Imperato (Introduction)

101 + Careers in Public Health, Second Edition
by Beth Seltzer (Author)

Introduction To Public Health
by Mary-Jane Schneider (Author)

The Public Health Crisis Survival Guide: Leadership and Management in Trying Times
by Joshua M. Sharfstein (Author)

Betrayal of Trust: The Collapse of Global Public Health
by Laurie Garrett (Author)

Best Science Podcasts 2018

We have hand picked the best science podcasts for 2018. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Why We Hate
From bullying to hate crimes, cruelty is all around us. So what makes us hate? And is it learned or innate? This hour, TED speakers explore the causes and consequences of hate — and how we can fight it. Guests include reformed white nationalist Christian Picciolini, CNN commentator Sally Kohn, podcast host Dylan Marron, and writer Anand Giridharadas.
Now Playing: Science for the People

#482 Body Builders
This week we explore how science and technology can help us walk when we've lost our legs, see when we've gone blind, explore unfriendly environments, and maybe even make our bodies better, stronger, and faster than ever before. We speak to Adam Piore, author of the book "The Body Builders: Inside the Science of the Engineered Human", about the increasingly amazing ways bioengineering is being used to reverse engineer, rebuild, and augment human beings. And we speak with Ken Thomas, spacesuit engineer and author of the book "The Journey to Moonwalking: The People That Enabled Footprints on the Moon" about...